Abrasive disk holding spindle for dental engine



(No Model.)

W. P. 000KB. A BRASIVE DISK HOLDING SPINDLE FOR DENTAL ENGINE.

No. 290,401. Patented Dec. 18, 1883.

I five-air:

wallima UNITED STATES PATENT OFFI E.

\VILLIAM P. OOOKE, OF MILFORD, MASS, ASSIGNOR TO THE NEW ENGLAND DENTAL MANUFACTURING COMPANY, OF PORTLAND ME.

ABRASIVE DISK-HOLDING SPINDLE FOR DENTAL ENGINES.

SPECIFICATION forming part of Letters Patent No. 290,401, dated December 18, 1883.

Application filed November 5, 1883. (No modeL) To all whom it may concern:

Be it known that I, WILLIAM P. COOKE, of Milford, county of Worcester, State of Massachusetts, have invented an Improvement in Abrasive Disk-Holding Spindles for Dental Engines, of which the following description, in connection with the accompanying drawings, is aspecification, like letters on the drawings representinglike parts.

This invention has for its object the production of a disk-holding spindle for use in dental engines; and it consists,essentially, in a spindle provided with ascrew-thread, and beyond the latter,and nearer the outer end of the spindle,with a concaved annulus or holder adapted to bear upon one side of the abrasive disk at a point outside its center, the said spindle having co-operating with it a screw, the head of which acts against the outer side of the disk, 7

while the threaded shank of the screw is extended loosely through the annulus and entered into the threaded hole of the spindle, as will be hereinafter described. The holding screw will preferably have its neck next its head of irregular shape in cross-section, and the hole through the emery-paper disk will be of corresponding shape, such construction enabling the neck of the screw to act to prevent the turning of the disk independently of the screw.

Figure 1 represents in perspective a spindle and disk attached to it in accordance with my invention. Fig. 2 represents the disk and screw on a larger scale; Fig. 3, the spindle with the outer end partially in section, and Fig. 4 a rear or right-hand side view of Fig. 2.

The spindle a has its rear end, a, shaped to be fitted to the shaft of a dental engine, all as usual. The abrasive disk 12, preferably of cut away natural teeth when in place,preparatory to filling, &c. The spindle a, near its forward end, is provided with a threaded recess, a and beyond it the spindle has applied to it a concaved annulus or holder, a the thin rim 2 of which rests against the rear side of the disk I) somewhat distant fromits center, as represented by the dotted lines, Fig. 4, leaving a space between the said annulus and the neck and shank 5 of the screw 0, which is extended through the disk from its outer side. The head of the screw cat one side of the disk I) clamps the said disk between it and the edge 201? the annulus or holder at, there being a spacebetween the neck of the screw and the edge 2 for the reception of the burr at the center of the disk, the said burr being formed by punching the center hole in the disk. Making the clamping-surface at the rear side of the disk as a 7 ring, and larger in diameter than the spindle or the neck 4 of the screw, enables the thin disk to be held firmly and without such strain astends to throw the disk out of true. The neck 4 of the screw being of irregular cross-section rather than cylindrical, it being herein shown as triangular, enables the disk and screw to be rotated always in unison and without slip one on the other. The screw-threaded shank 5 of the screw 0, when extended through the disk, as in Fig. 2, will be extended through the covered annulus and engaged withthe threaded recess a of the spindle, the threads being out in such direction that the working strain on the disk tends to tighten the said screw in the spindle; but when it is desired to withdraw the screw 0 from the spindle a,to remove disk I) and sub stitute for it a new one, or one of another size or grade of fineness, then the engagement of the disk, its center opening fitting the neck of the screw, may be used as a means for starting the screw outward. The thin annular edge 2 of the holder (6", acting against the rear side of the disk I), affords abetter holding means than were the front or acting face of the part (0 made as a fiat surface provided with a threaded hole equal to the diameter of the shank of the screw,

edge 2, so that the disk is clamped firmly by two narrow annular surfaces at a tance from the center.

I claim-- 1. The spindle a, provided with the threaded recess and the annular holder, combined little dis with a screw, 0, adapted to extend through the center of and hold the disk I), substantially as described.

2. The screw 0, having a neck irregular in cross-section, and the disk I), provided with a central hole corresponding in shape with the cross-section of the neck of the said screw and applied to the said neck, combined with the spindle a, provided with the threaded recess, and with the annular holder applied to the end of the spindle, the said holder having a thin annular face, 2, to come in contact with the rear side of the said disk at a point outside the neck of the screw,lcaving a space between the said neck and face 2 for the reception of that part of the disk immediately about the said neck, substantially as described.

VILLIAM I. COOKIE.

\Vitnesses:

G. W. Gnnoony, B. J. NOYES. 

